Plastic additives and fillers are compounds used to mix into plastic raw materials during the production process, with the aim of changing some of their properties. While additives are created purely to modify plastics, adding to them properties that were not originally present to satisfy a wider range of uses, fillers (also known as fillers) – filler) is used with the goal of reducing material costs
What is plastic filler?
Fillers are basically materials that can be mixed into another material and form a mixture. If we ignore the performance and processability of the final mixture, any material can be used as a filler, as long as it and the main material can blend well together. With the important goal of reducing raw material costs, fillers are a large market, with current annual output estimated at about 53 million tons, produced by more than 700 companies worldwide. world. Although fillers can be used in a wide variety of materials, their two largest segments are elastomers and plastics. With the long-term trend of plastic counterfeiting inevitably increasing as oil and gas abundance declines, combined with times when plastic prices spike due to market fluctuations, mineral fillers with abundant supply and much lower prices are becoming increasingly commercially attractive.
In the past, using fillers to mix into plastic materials was considered a trick of manufacturers. By blending a cheaper ingredient into the main ingredient, they can earn more profits, giving themselves a competitive advantage in terms of cost. Previous use of fillers will almost certainly cause the performance and quality of the product to be significantly reduced. Finding ideal filler blends that do not reduce quality can be considered a great success. Such recipes are always kept secret. Accepting lower profits when using 100% virgin plastic resins, in order to create products of superior quality, has been the pride of many businesses, including our company. Most people believe that plastic containing fillers is a cheap commodity and should only be used in the secondary market. Their characteristics are that the product surface lacks perfection, the color is opaque and is easily punctured, torn,
But with the development of materials science, those things may no longer be true. Modern fillers today no longer reduce the performance of plastic too much, and can even improve the product, adding unique properties to the plastic that the plastic material itself does not have. With the most popular filler being CaCO3, also known as Taical plastic, many tests have shown that at a 5% mixing level in LDPE plastic, the tensile strength and yield in both the transverse and machine directions (TD and MD) are improved. At 11% to 20% CaCO3, the tensile strength decreases but is not lower than the unmixed level, but in return the puncture resistance and sawing strength increase. At this mixing ratio, the resin and CaCO3 mixture also creates less pressure on machine parts, allowing the screw speed to increase with unbalanced current intensity. That means output can increase higher than normal. The anti-clumping ability is also much improved, allowing you to further reduce costs for this type of additive.
The typical roughness of the plastic film surface using CaCO3 filler is sometimes not entirely a defect. Such surfaces can improve the adhesion of ink, making them very suitable for printing. We can even eliminate the corona treatment step in the production process with a suitable filler content.
Undeniably, competitive price pressure is the leading reason why manufacturers are interested in fillers. But the truth is that mixing plastic with fillers is becoming more and more interesting. If we understand their properties, we can create many outstanding ingredient formulas. Perhaps that is why manufacturers are becoming more and more reckless about the level of fillers in their products. Many domestic manufacturers have successfully produced high-quality plastic bags with filler content up to 25%, a rate never before seen in blown film applications. Even some savvy customers have begun to specify the amount of fillers in the products they order to reduce costs.
Indeed, fillers in the plastic industry are gradually eliminating negative stereotypes and are no longer considered a “bad word” in the industry. In the near future, companies like us that have traditionally used 100% virgin plastic as raw materials may also have to change their perspective.
In theory, any material that can be converted into granules can be used as a filler for plastics. For example, we can use sand as a filler, and the end result is that the plastic will have sand particles mixed in. The possibilities for combining plastic with other materials are endless, but for material mixing to be successful, the filler needs to melt and disperse well in the plastic mixture. At a higher level of technical requirements, they must be chemically inert, contain no metal impurities to avoid degrading the plastic, have low hardness to avoid abrasion of equipment, and most importantly, cost is low. must be cheap and readily available to be suitable for commercial use.
There is no perfect resin, and no filler is ideal. The essence of using fillers is a compromise between the properties that will be improved and those that will be lost. To get the best trade-offs, manufacturers need to understand the properties of fillers, and how they will interact with the resin.
